Hi folks, (I'm not subscribed to the list, so please CC me on all responses.)
This is using GCC 5.2 on Linux x86_64. On a project at work I've found that one of our shared libraries refuses to link because of some symbol references it shouldn't be making. If I add "-fno-devirtualize -fno-devirtualize-speculatively" to the compile flags, the issue goes away and everything links/runs fine. The issue does *not* appear on GCC 4.8 (which is used by our current production toolchain). First of all, does anyone have any ideas off the top of their head why devirtualization would break like this? Second, I'm looking for any ideas on how to gather meaningful data to submit a useful bug report for this issue. The best idea I've come up with so far is to preprocess one of the sources with the incorrect references and use 'delta' to reduce it to a minimal preprocessed source file that references one of these incorrect symbols. Unfortunately this is a sluggish process because such a minimal test case would need to compile correctly to an object file -- so "delta" is reducing it very slowly. So far I'm down from 11MB preprocessed source to 1.1MB preprocessed source after running delta a few times. - Steven
